Limitations of variable shaped electron beam lithography for advanced research and semiconductor applications

This paper reports on the study of limitations of variable shaped electron beam lithography (EBL) as flexible high-resolution pattern generators for the fabrication of high quality photomasks required for many applications in sensors and microsystems development, including packaging applications. For this purpose, the case of 50×50 nm
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electron beam shape at 40 keV electron energy and a high-resolution e-beam resist Hydrogen Silsesquioxane (HSQ) were utilized. Various process parameters, which determine the accuracy of the resist profiles and the size of structures, such as solubility rates, dependences of the linewidth on the exposure dose, lithographic resolution, etching capabilities of HSQ and their influence on the limitations of variable shaped EBL, are studied.